One Belfast teenager is being hailed as a hero after preventing a man setting fire to himself outside the city hall. 

A video of the incident shows the man lighting a piece of cloth on the ground before covering himself in white spirit and shouting "fuck the system." He also sprayed the liquid at a young girl and others.

Paul Russell, an 18 year-old from Belfast, realised the danger and tried to restrain him. Russell approached and shoved the man, who then slipped in a puddle of the liquid before being pinned to the ground by a number of people.

Speaking to the Belfast Telegraph, Russell said that he had initially thought it was some sort of street performance. When the man started throwing the liquid at others while screaming, he decided to intervene: "I don't know if I punched him or pushed him, I just wanted to get him away from the fire."

Police arrived on the scene shortly after and tasered the man as he resisted arrest. He is currently being held under the Mental Health Act.